Developmental disfluency and emerging grammar. I. Disfluency characteristics in early syntactic utterances.

Approximately 47,200 spontaneous utterances of four nonstuttering children were analyzed for the occurrence of developmental disfluency from the time of one-word utterances through the emergence of beginning syntax. Disfluency profiles were drawn for each child at each of four mean length of utterance (MLU) levels. The frequency of total disfluency and the frequency and distribution of specified disfluency types were computed. Variations were found among the children's profiles with systematic changes in disfluency profiles for the individual child at each succeeding MLU level. The observed changes were related to the psycholinguistic features of discourse, imitation, and grammatical complexity in the children's language development.